The objective of this study is to provide information relative to an assessment of the extent of hazard to public health created by the use of antibacterial drugs in raising domestic animals and poultry for food production purposes. It is the intent of this research 1) to evaluate through pharmacokinetic studies the likelihood that consumable meat and animal by-products contain antibacterial drug residues and metabolites as a result of currently approved drug administration practices and to obtain information regarding the sensitizing, toxic, and antibacterial properties of the drug residues and metabolites, and 2) to distinctly define and characterize the influence of the agricultural uses of antibacterial drugs upon the emergence of antibacterial drug resistant human pathogens and the formation of a reservoir of antibacterial drug resistance for the human microflora and human pathogens.